The present invention relates to a motor-driven appliance and a battery pack.
In a motor in which permanent magnets are used, when a current flowing in the motor (specifically, a current flowing in an armature) has become excessively large, demagnetization of the permanent magnets is caused under the influence of a magnetic field generated from the armature, depending on a level of the excessively large current. Since demagnetization of the permanent magnets in the motor causes a change in characteristics of the motor, it is necessary to take some measures to suppress occurrence of demagnetization.
JPH09-285977 describes a technique in which, in order to prevent demagnetization due to a rush current at the time of activation of a motor, a resistor is inserted in a current path to the motor, and in which control is performed by a triac so that the current flowing at the time of the activation rises gradually.